Method and apparatus for processing coiled sheet metal

ABSTRACT

A method and apparatus for processing coiled sheets of metal. The metal is uncoiled, flattened, stretched, sheared and stacked by a continuous in line apparatus. Grippers which hold the sheet during the stretching operation open to allow the metal to pass through in a continuous sheet; thus, alleviating the necessity for transfer of the sheet to an additional processing apparatus.

United States Patent Roper 1 Aug. 29, 1972 [54] METHOD AND APPARATUS FOR PROCESSING COILED SHEET METAL [72] Inventor: Ralph E. Roper, Indianapolis, Ind.

[73] Assignee: Wallace Expanding Machines, Inc.,

Indianapolis, Ind.

[22] Filed: March 16, 1970 [21] Appl. No.: 19,868

[52] US. Cl. ..72/302, 72/294, 72/31 1, 72/183, 72/161, 242/786 [51] Int. Cl. ..B2ld 1/05 [58] Field of Search ..72/183, 161 205, 129, 130,.

[56] References Cited UNITED STATES PATENTS 3,103,964 9/ 1963 Rahn ..72/129 3,150,706 9/ 1964 O'Brien; ..72/183 2,714,917 8/1955 Siegerist ..L ..72/27 3,397,565 8/1968 Ritter et a1 ..72/183 X 1,811,599 6/1931 Thomas ..72/183X 2,364,376 12/1944 Labe ..-.72/183 X 2,477,083 7/1949 Picton ..72/ 161 X 2,449,507 9/1948 Pope ..72/302 2,869,241 1/1959 Witt ..72/11 X 3,151,506 10/1964 Hunt ..72/14 X 3,429,164 2/1969 Oganowski et al. ..72/202 3,343,393 9/1967 Groll ..72/183 Primary ExaminerMilton S. Mehr AttorneyWoodard, Weikart, Emhardt & Naughton [57] ABSTRACT A method and apparatusfor processing coiled sheets of metal. The metal is uncoiled, flattened, stretched, sheared and stacked by a continuous in line apparatus.

, Grippers which hold the sheet during the stretching operation open to allow the metal to pass through in a continuous sheet; thus, alleviating the necessity for transfer of the sheet to an additional processing apparatus.

8 Claims, 13 Drawing Figures PATENTED M1929 m2 SHEEI 1 [IF 5 INVENTOR. PAL PH E. ROPE? a/mflMa-M 72 ATTORNEYS mcminwcz Ian 3; see; 921

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ATTORNEYS METHOD AND APPARATUS FOR PROCESSING COILED SHEET METAL BACKGROUND OF THE INVENTION 1 Field of the Invention This invention relates to a metal deforming apparatus, whereby coiled metal is stretched to flat sheets.

2. Description of the Prior Art A number of devices have been devised for flattening sheet metal. Three such devices are-illustrated in the US. Pat. to Wells No. 2,897,871, the US. Pat. to Siegerist No. 2,714,917 and the US. Pat. to Pope No. 2,449,507. These devices grip the ends of the sheet and stretch it in order to achieve the flatness desired.

In order to use one of these devices for flattening coiled sheet metal, additional machines and processing are required, resulting in added time and expense. For example, none of the above devices include a coil peeler for feeding the sheet into the stretching apparatus. Some sheets of metal are sufficiently thick so as to prevent manual peeling. In addition, it is desirable to have the device cut the coiled sheet into the lengths desired and to cut off any damaged sections of the sheet. Consequently, the present invention provides a method and apparatus for completely converting a coiled sheet of metal into a stack of flat sheets of the desired length.

SUMMARY OF THE INVENTION The present invention provides a method and apparatus for rotating a coil of metal, peeling the leading edge of the sheet metal from the coil, stretching the sheet beyond the elastic limit to obtain the flatness required, shearing the sheet into lengths desired and stacking the sheared sheets.

It is an object of this invention to provide a method and apparatus for controlling the flatness in a sheet of metal.

It is also an object of this invention to provide a method and apparatus for converting coiled metal into flat sheets by a continuous in line process.

It is a further object of this invention to provide a method and apparatus for converting coiled metal into stacked sheets of the desired length by a continuous in line process.

'The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top view of the coil processing machine.

FIG. 2 is a side view of the coil processing machine.

FIG. 3 is an enlarged end view of the coil loading car taken along the line 33 of FIG. 2 in the direction of the arrows.

FIG. 4 is a side view of the coil loading car shown in FIG. 3.

FIG. 5 is an enlarged view of the rotatable coil holder taken along the line 5-5 of FIG. 2 in the direction of the arrows.

FIG. 6 is an enlarged view of the coil peeler taken along the line 6-6 of FIG. 2 in the direction of the arrows.

FIG. 7 is a side view of the coil peeler shown in FIG. 6.

FIG. 8 is an enlarged side view of the coil flattener and feeder taken in the direction of arrows 88 in FIG. 1.

FIG. 9 is an enlarged top view of the stretching device taken in the direction of arrows 9-9 in FIG. 2.

FIG. 10 is a side view of the stretching device shown in FIG. 9.

FIG. 11 is an enlarged view taken in the direction of arrows 11-11 in FIG. 2.

FIG. 12 is a side view of the structure shown in FIG. 11.

FIG. 13 is an enlarged fragmentary view of a gripper with associated parts taken in the direction of arrows l3-13 in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT For the purpose of promoting an understanding of the principles-of the invention, reference will now be made to the embodiment illustrated in the drawings, specific language will be used to describe the same. It will nevertheless be understood that no limitations to the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein, being contemplated as would normally occur to one skilled in the art to which the invention relates.

GENERAL OPERATION Referring now more particularly to FIGS. 1 and 2, there is illustrated a coil processing machine 30 which includes a coil loading'car 31. The coil loading car receives a metal coil and carries the coil to the rotatable coil holder 32. Adjacent to the coil holder is the coil peeler 33. As the coil is rotated by the coil holder 32 the coil peeler 33 grasps the leading edge of the 'coiled sheet and feeds it to the coil flattener and feeder 34.

As shown in FIGS. 1 and 2, the metal sheet then proceeds through stretching device 37. The stretching device 37 is composed'of a traveling hydraulic clamp car 36, rollers 35, a stretcher head 38 and measuring rollers 39. The traveling hydraulic clamp car 36 is located at a distance from the stretching head 38 equal to the length of sheet metal to be stretched. Upon proper location of the traveling hydraulic clamp car, grippers within the clamp car 36 and the stretching head 38 bite into the sheet of metal and hold the sheet metal in a fixed location. Thereupon, the sheet of metal is stretched by moving the stretching head 38 in the direction away from the traveling hydraulic clamp car 36. The clamp car 36 is held in a fixed position during the stretching operation while the stretching head 38 is moved by power cylinders. A series of rollers 35 support the sheet metal while the sheet passes through the stretching device 37. The sheet metal then passes through measuring rollers 39 which measure the length of the sheet metal.

The sheet metal exits the stretching device 37 and passes through the exit pinch rollers 40. The pinch rollers provide force to feed the sheet metal to power shear 41. The power shear is operated to cut the leading and rear portions of the sheet marred by the grippers. These portions fall into scrap car 42 while the remaining undamaged sheet passes across conveyor belt 43 and onto air stacker 44. The sheet metal is then stacked on the stock car 46.

con. LOADING CAR The purpose of the coil loading car 31 is to receive a coil of metal and carry it to the rotatable coil holder 32. The coil loading car aligns the coil in a vertical and horizontal direction with respect to the chucks of the rotatable coil holder 32.

Shown in FIGS. 3 and 4 is the coil loading car. The coil of metal is received by two cradle rollers 51 rotatably mounted in a rectangular holder 63. The rectangular holder 63 is supported by member 64 which is fastened to a slidable piston rod 62 of hydraulic cylinder motor 52. The hydraulic cylinder motor 52 is mounted to the forward section of car frame 47. The piston assembly extends below the car frame and through the opening between rails 54 and 56. A cavity is provided beneath rails 54 and 56 to allow clearance for the piston assembly during horizontal movement of the coil loading car.

The coil of metal is horizontally aligned with chucks 72 and 71, FIG. 5, of the rotatable coil holder by moving the coil loading car on rails 54 and 56. Vertical alignment is provided by operating hydraulic cylinder motor 52. The cylinder 52 provides vertical movement to the coil of metal by forcing slidable piston rod 62 against member 64 which supports rectangular holder 63 and rollers 51.

Horizontal movement of the coil loading car is controlled by motor 53 which is supported by bracket 65 mounted on the rear vertical wall of car frame 47. Motor 53 provides power through an axle-gear mechanism 69 to gear 58 which drive gear 57 mounted on axle 59. Axle 59 is mounted to the rear section of car frame 47. Wheels 55 and 60 are mounted to the ends of axle 59. Connected to the forward portion of the car frame 47 is an axle 67 with a wheel mounted at each end. The two wheels on axle 67 rest on rails 54 and 56.

A safety bar 61 is located at the end of the coil loading car, to prevent a coil of metal from falling off the rear end of the car should it become disengaged from the coil rollers 51. The safety bar has two horizontal bars fastened to two vertical bars. The two vertical bars are fastened to the rear section of car frame 47.

Electrical power to operate motor 53 and the hydraulic cylinder motor 52 is provided by an external power source through flexible cable 66. The flexible cable connects to the coil loading car through a standard commercial connector located on bracket 68 mounted to the rear section of car frame 47. The cable freely bends and does not impede the horizontal movement of the coil loading car.

ROTATABLE COIL HOLDER The purpose of the rotatable coil holder 32 is to receive the coil of metal 50 from the coil loading car 31 and rotate the coil in order that the coil peeler 33 can feed a continuous sheet of metal to the coil flattener and feeder 34.

Referring to FIG. 5, a coil of metal 50 is shown being held by the rotatable coil holder 32. Holding the coil are two circular chucks 71 and 72. The coil holder is composed of two identical sections 73 and 74. Section 73 will be described, it being understood that a similar description applies to section 74.

Section 73 is shown in the left hand side of FIG. 5. The main frame 89-of section 73 in conjunction with vertical bracket 88 supports axle 85. Axle 85 is rotatably mounted by standard bearings within the main frame 89. Cylindrical chuck 72 is mounted on the end of axle 85 which has various sized hubs 82 and 78 for receiving the drive belt 79. Belt 79 is driven by axle 84 which receives its power from motor 77. Motor 77 is mounted on bracket 70 and provides power through a gear-axle assembly 70' mounted to the top wall of section 73. Bracket 70 is fastened to the side wall of gear axle assembly 70'. Axle 84 extends from gear-axle assembly 70' and has different sized hubs 80 and 81 for receiving belt 79. By adjusting belt 79 to the different hubs of axle 84 and 85, different rotational speeds of cylindrical chuck 72 may be achieved. Cylindrical chuck 72 has three hubs of different diameters for piercing the center of the coil of metal 500 Section 73 is slidably mounted on rails 86 which are mounted to I-beams 87. Rails 86 allow section 73 to move horizontally in order to engage and disengage the metal coil 50. The horizontal movement of section 73 is controlled by hydraulic cylinder motor 75. The piston rod is connected to bracket 71' mounted to the bottom wall of main frame 89. Cylinder 75 is horizontally mounted to I-beams 87. Operation of cylinder 75 results in the necessary force being applied to bracket 71' to move section 73.

Section 74 is shown on the right hand side of FIG. 5 and is identical to section 73. That is, power is applied by motor 83 through a axlegear assembly 72' and a belt-axle device to rotate cylindrical chuck 71. Chuck 71 is rotatably mounted to an axle as chuck 72 is rotatably mounted to axle 85. Section 74 is slidably mounted on rails 86 which are mounted to I-beams 87. Section 74 has a bracket identical to bracket 71 of section 73 and is moved in a horizontal direction by hydraulic cylinder motor 76 as section 73 is moved by hydraulic cylinder motor 75.

Sections 73 and 74 must be operated as a unit. That is, cylindrical chuck 72 .must be driven at the same speed as cylindrical chuck 71 The two chucks may be driven in a clockwise or counterclockwise direction depending on which direction the metal sheet is to be moved. Sections 73 and 74 are moved back by pistons and 76 to allow the coil loading car access to place the coil of metal in a position for the cylindrical chucks to engage.

COIL PEELER The purpose of the coil peeler 33 is to grasp the leading edge of the coil of metal being rotated by the rotatable coil holder and to feed it to the coil flattener and feeder. Referring to FIGS. 6 and 7, the coil peeler consists of two vertical beams 90 with brackets 103 and 104 which support horizontal I-beams 91 and 105. Fastened to the horizontal I-beam 91 is a hydraulic cylinder motor 92. The end of the sliding piston shaft 93 is rotatably fastened to the top of member 94 which is rotatably mounted by rod 106 to vertical beams 90. Slidably mounted to member 94 are two shafts 95 and 96. The coil peeler blade 97 attaches to the bottom ends of shaft 95 and 96. A hydraulic cylinder motor 100' is mounted to the side of member 94 nearest roller 98 with slidable piston rod 101 extending toward blade 97. The free end of rod 101' is attached to horizontal member 102' which is fastened at either end to shafts 95 and 96. The coil peeler is operated by energizing hydraulic cylinder motors 92, 100 and 100. Operation of cylinder 92 causes member 94 to pivot. Operation of cylinder 100' causes blade 97 to move in a vertical direction. By operating cylinder 92 and 100, the coil peeler blade 97 must be placed next to the coil of metal 50. The coil of metal is rotated resulting in the coil peeler blade 97 disengaging the end of the coil of metal. Two hydraulic cylinder motors 100 are pivotally mounted at one end in a cavity beneath the floor while supporting a pivoted guiding member 101. Member 101 is rotatably mounted by rod 107 to vertical beams 90. The guiding member 101 has a flat surface which supports the lower surface of the sheet of metal peeled away from the coil of metal. The hydraulic cylinder motors 100 operate to abut member 101 against the sheet metal. As shown in FIG. 7, with the coil rotating in a counterclockwise direction the edge of the coil peeler blade 97 forces the sheet against the surface of the guiding member 101 until the end of the sheet metal is fed between the two input rollers 98 and 99 of the coil flattener and feeder 34. Once the sheet metal passes through rollers 98 and 99, the coil peeler blade 97 swings from the coil and is no longer utilized.

COIL FLATTENER AND FEEDER Referring to FIG. 8, the coil flattener and feeder 34 receives the sheet of metal from the coil peeler 33 through rollers 98 and 99. The sheet is then processed through a plurality of flattening rollers 1 10.

Roller 98 is rotatably mounted in holder 108 which is slidable in channel 109 of the main frame 102. Holder 108 is fastened to the end of power lead screw 114. Lead screw 114 is engaged by a gear-motor device 115 located at the top of main frame 102. Roller 98 may be adjusted up or down by gear-motor device 115. Likewise, roller 99 is rotatably mounted in holder 116. Holder 116 is connected to the end of slidable piston rod 117 of hydraulic cylinder motor 118 mounted in the lower portion of main frame 102. By operating gear-motor device 1 and hydraulic cylinder 118, the gap between rollers 98 and 99 may be increased to receive the sheet of metal and decreased once the sheet has passed through the rollers. In addition, rollers 98 and 99 may be adjusted to the corresponding height of the incoming sheet.

The flattening rollers 110 are rotatably mounted in holders 1 19 and 119'. The rollers are mounted to form top and bottom rows. The sheet metal passes between the top row of rollers and bottom row of rollers. Connected to holders 119 are power lead screws 111 driven by motors 118' mounted to the top of main frame 102. Connected to holders 1 19' are piston rods operated by hydraulic cylinder motors 112 mounted to the bottom of main frame 102. By adjusting cylinders 1-12 and motors 118', the gap between the top and bottom rows of rollers may be increased or decreased in order to change the pitch through which the sheet passes. Meters 113 indicate the amount of pitch which the sheet must pass through. The bending of the sheet metal by rollers 110 in FIG. 8 is exaggerated for illustrative purposes.

The flattening rollers are rotated by a motoraxle mechanism not shown. The flattening rollers are positively driven in order to pull the sheet metal through the coil flattener and feeder. Each roller is connected to an axle which in turn is driven by a suitable motor.

STRETCHING DEVICE The stretching device 37 is shown in FIGS. 9 and 10. The purpose of the device is to grip both ends of the sheet metal and stretch the sheet beyond its elastic limit until the necessary degree of flatness is achieved.

The sheet metal enters the stretching device from the coil flattener and feeder into the entrance guide 120 and out through a set of rollers 39. The entrance guide 120 supports one end of the two side walls 123 which are supported at their other ends by two reinforced concrete posts 130. The entrance guide 120 and concrete posts also support two powered lead screws 125. The lead screws 125 are mounted in such a manner that the screws may be rotated. Motor mounted at the top of the entrance guide drives two axles 141 mounted on either side of the motor. The two axles 141 provide power through gears 142 to drive the power lead screws 125.

Also shown in FIGS. 9 and 10 is the traveling hydraulic clamp car 36. The car rides on four wheels 143 rotatably mounted to brackets 142' fastened to the main frame of the car. Wheels 143 are spaced to ride on two rails 131. Mounted in the clamp car are two threaders 145 for receiving the two powered lead screws 125. The traveling hydraulic clamp car 36 may be moved on rails 131 to or from stretching head 38 by operating motor 135 to turn powered lead screws 125. Car 36 will move in a horizontal direction as the powered lead screws 125 rotate since the car is threaded on the screws by two threaders 145. Grippers 128 and 129 are mounted on the clamp car side wall nearest the entrance guide. As shown in FIG. 13, the top grippers 128 are rotatably mounted to brackets 144 fastened to the frame of clamp car 36. Also mounted to brackets 144 are hydraulic cylinder motors 126 which .are connected to grippers 128 in such a manner as to pivot the grippers. The bottom grippers 129 are mounted in a similar way to hydraulic cylinder motors 126' only partially shown in FIG. 10. The sheet metal passes between grippers 129 and 128 and also through an opening provided in clamp car 36. The sheet metal may be secured by forcing grippers 128 and 129 against the sheet through operation of cylinders 126 and 126'.

Supporting the sheet of metal as it passes through the stretching device are rollers 35, shown in FIGS. 9 and 10. The rollers are linked together on a continuous track arrangement that adjusts as the movable clamp car is relocated. The pinch rollers 40 and coil flattener and feeder 34 power the sheet through the stretcher.

Stretching head 38 rides on four wheels 146 rotatably mounted to brackets 147 fastened to the frame of the stretching head. The four wheels are spaced to ride on rails 139. Grippers 133 and 134 are mounted on the stretching head side wall nearest rollers 39. The top grippers 133 are rotatably mounted to brackets 148 along with hydraulic cylinder motors 149. Brackets 148 are fastened to the frarne of the stretching head 38. Cylinders 149 are connected to grippers 133 in such a way that operation of the cylinders force the grippers to pivot. The bottom grippers 134 are mounted in a similar way to the bottom hydraulic cylinder motors 149' only partially shown in FIG. 10. The sheet metal passes between grippers 133 and 134 and also through an opening provided in stretching head 38. The sheet metal may be secured by forcing grippers 133 and 134 against the sheet through operation of cylinders 149 and 149'.

F astened to the side walls of the two concrete posts 130 are two power cylinders 136 each containing a power piston 137 for forcing stretching head 38 toward rollers 39 and thereby causing the sheet metal to be stretched. Power pistons 137 each abut against members 137 which are mounted to the side wall of stretching head 38. In some cases, power pistons 137 may apply sufficient pressure to stretching head 38 causing the sheet of metal to break with the result that stretching head 38 may move against and damage exit frame 148'. Thus, hydraulic shock absorbers 140 are mounted to the side wall of exit frame 148' nearest head 38. The shock absorbers are of standard design having a piston in a chamber filled with hydraulic oil. When a load is applied by stretching head 38 against the shock absorber piston, the piston applies pressure to the oil forcing the oil out an orifice in the chamber. The orifice allows a controlled amount of the oil to flow out of the chamber and thereby creates a decelerating action on stretching head 38.

As the leading edge of the sheet metal reaches the measuring rollers 39, the movement of the sheet metal is stopped by disengagement of the rotatable coil holder 32 and the positively driven flattening rollers 110. The traveling hydraulic clamp car 36 is moved to a point located at a distance from stretching head 38 equaling the length of sheet to be stretched by operation of the two powered lead screws 125. These lead screws allow the operator to adjust the distance quickly. Cylinders 126, 126', 149, and 149 are exercised forcing grippers 128, 129, 133, and 134 to bite into the sheet to the extent necessary preventing the sheet from being moved. The sheet is then stretched by operating the two power cylinders 136 forcing stretching head 38 away from clamp car 36. After the metal is stretched, the rotatable coil holder 32, pinch rollers 40 and flattening rollers 110 are operated to move the sheet through measuring rollers 39. Rollers 39 are rotatably mounted in exit frame 148' and indicate on a standard roll counter the length of sheet passing through the rollers.

POWER SHEAR After the plate has been stretched so that it assumes an entirely flattened configuration, the sheet metal then passes through the exit pinch rollers 40 shown in FIGS. 11 and 12 onto the power shear 41. The exit pinch rollers 40 and the shearing device 41 may be operated in such a manner that the stretched sheet may be cut into increments. For example, a 48 foot stretched length may be cut up into six pieces, 8 feet long each.

The exit pinch rollers 40 are composed of two rollers, one which passes on the top surface of the sheet metal and one which passes on the lower surface of the sheet metal. The rollers are slidably mounted in vertical shaft 180 located in both sides of frame 170. The exit pinch rollers are positively driven in order to provide the force necessary to move the sheet of metal through the power shear. Motor provides the power necessary to drive the exit pinch rollers by a gear and axle mechanism 151.

Referring to FIGS. 11 and 12, the power shear 41 is composed of two offsetting blades 152 and 153. Blade 152 is stationary while blade 153 moves in a vertical direction. When the power shear 41 is not in use the sheet of metal passes through blades 152 and 153 over the scrap car 42 and onto the air stacker 44. The power shear is operated to cut off the leading edge of the sheet metal which has been damaged by the grippers of the stretcher head 38. Controls are connected to shearing device 41, exit pinch rollers 40 and measuring rollers 39 for selecting the desired length of cut sheet. The controls may be operated manually by the operator and/or automatic controls may be utilized to pre-program the length of cut sheet. In addition, the power shear is utilized to cut off the trailing edge of the sheet of metal which has been damaged by the grippers of the traveling hydraulic clamp car 36. The damaged portion of sheet metal which is cut off falls into the scrap car 42. The undamaged portion passes to the conveyor belt 43 and then to the air stacker 44.

The scrap car 42 is a rectangular box mounted on four wheels which rest on rails 154 and 155. The scrap car may be moved from the processing machine 30 in order to allow emptying.

AIR STACKER The air stacker 44 receives the sheet metal from the conveyor belt 43 onto stock car 46. As the sheet feeds off of conveyor belt 43, the sheet is supported by a film of air. This film separates the incoming sheet from the stacked sheets on car 46 in order to prevent marring of the sheet. Once the sheet is into position, its weight overcomes the air film support pressure and it gently settles down onto the stack of sheets. The stack is removed by rolling the car 46 from under the stacker frame. Such an air stacker is commercially available and could be Model No. AH manufactured by 'Alvey Conveyor Mfg. Co. of St. Louis, Missouri.

It will be evident from the above description that the present invention provides a method and apparatus for processing coiled sheet metal. One important advantage found in the invention is that the coiled sheet is converted into flat sheets by a single in-line process. As a result, the process is most efficient since the process is accomplished quickly without the customary handling steps.

It will be further evident that the present invention provides a method and apparatus of controlling the flatness in a sheet of metal. In addition, the final sheet is free of the customary surface defects and scratches.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

The invention claimed is: l. A coil processing machine comprising:

a rotatable coil holder for receiving a coil of metal, said holder having chucks for holding and rotating said coil;

a coil peeler having a blade and guiding member for grasping the leading edge of said coil;

a coil flattener and feeder having input rollers for receiving the leading edge of said coil from said coil peeler, and having flattening rollers for flattening the sheet of metal;

a stretching device for'stretching said sheet beyond the elastic limit until the necessary amount of flatness is obtained; said device having a traveling hydraulic clamp car and a stretching head, said car and said head having grippers for grasping said sheet, said device having power cylinders for applying force to said stretching head to cause said stretching head to move from said car and to cause said sheet to be stretched;

a power shear for cutting off the portions of said sheet marred by said grippers;

a stock car for receiving stretched sheets.

2. The combination of claim 1 and further comprisan air stacker for receiving stretched sheets of metal from said power shear and transferring said stretched sheets to said stock car, said stacker having means emitting forced air for supporting said stretched sheet.

3. The combination of claim 2 and additionally comprising a scrap car for receiving the marred portions of 30 said sheet cut by said power shear.

4. The combination of claim 3 and additionally comprising exit pinch rollers for forcing said stretched sheet through said shear.

5. The combination of claim 4 and additionally comprising a coil loading car for carrying said coil to said I0 coil holder, said loading car having cradle rollers for holding said coil.

6. The combination of claim 1 wherein said stretching device contains measuring rollers for measuring the length of said stretched sheet.

7. The combination of claim 1 wherein said input rollers are adjustable to control the distance between said rollers.

8. A method for flattening sheet metal from a coi comprisingthe steps of:

rotating a coil of metal;

peeling the leading edge of the sheet metal from said coil;

stretching said sheet beyond the elastic limit to obtain the flatness required, said stretching step including the sub-steps of:

moving a pair of grippers apart a distance equal to a length of metal to be stretched;

gripping said metal with said grippers subsequent to said moving step;

locking one of said grippers in a fixed location subsequent to said moving step; and,

moving the other of said grippers away from said one gripper locked in place to stretch said metal; cutting said sheet into sections having desired lengths;

stacking the sections of said sheet;

feeding said edge to a set of rollers;

fl tte in said sheet b said rolle transferring said sheei during said stacking step with forced air; measuring the length of the stretched sheet after said stretching;'and wherein: I said cutting also removes portions of said sheet marred during said stretching.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTMN Patent NO. q, g yq D t d August f lnvencorg lph E. Roper It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 32 "drive" should be replaced by --drives-- Column 4, line 19 "500" should be replaced by --50.

Signed and sealed this 30th day of January 1973.,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. A coil processing machine comprising: a rotatable coil holder for receiving a coil of metal, said holder having chucks for holding and rotating said coil; a coil peeler having a blade and guiding member for grasping the leading edge of said coil; a coil flattener and feeder having input rollers for receiving the leading edge of said coil from said coil peeler, and having flattening rollers for flattening the sheet of metal; a stretching device for stretching said sheet beyond the elastic limit until the necessary amount of flatness is obtained, said device having a traveling hydraulic clamp car and a stretching head, said car and said head having grippers for grasping said sheet, said device having power cylinders for applying force to said stretching head to cause said stretching head to move from said car and to cause said sheet to be stretched; a power shear for cutting off the portions of said sheet marred by said grippers; a stock car for receiving stretched sheets.
 2. The combination of claim 1 and further comprising: an air stacker for receiving stretched sheets of metal from said power shear and transferring said stretched sheets to said stock car, said stacker having means emitting forced air for supporting said stretched sheet.
 3. The combination of claim 2 and additionally comprising a scrap car for receiving the marred portions of said sheet cut by said power shear.
 4. The combination of claim 3 and additionally comprising exit pinch rollers for forcing said stretched sheet through said shear.
 5. The combination of claim 4 and additionally comprising a coil loading car for carrying said coil to said coil holder, said loading car having cradle rollers for holding said coil.
 6. The combination of claim 1 wherein said stretching device contains measuring rollers for measuring the length of said stretched sheet.
 7. The combination of claim 1 wherein said input rollers are adjustable to control the distance between said rollers.
 8. A method for flattening sheet metal from a coil comprising the steps of: rotating a coil of metal; peeling the leading edge of the sheet metal from said coil; stretching said sheet beyond the elastic limit to obtain the flatness required, said stretching step including the sub-steps of: moving a pair of grippers apart a distance equal to a length of metal to be stretched; gripping said metal with said grippers subsequent to said moving step; locking one of said grippers in a fixed location subsequent to said moving step; and, moving the other of said grippers away from said one gripper locked in place to stretch said metal; cutting said sheet into sections having desired lengths; stacking the sections of said sheet; feeding said edge to a set of rollers; flattening said sheet by said rollers; transferring said sheet during said stacking step with forced air; measuring the length of the stretched sheet after said stretching; and wherein: said cutting also removes portions of said sheet marred during said stretching. 